AC compressor runs all the time

Hi and thanks for using 2CarPros.com.

There could be a number of things causing this issue. Interestingly, I really need to know what the high and low side pressure readings are when it is engaged. Here is why. There is a high side pressure sensor. The compressor cycles on when the pressure sensor on the high side of the system sends a signal that the pressure has dropped and the compressor needs to turn on to increase pressure. If the high side pressure is too low due to a blockage in the system, it will keep sending a signal to the control module to increase pressure, which in turn keeps the compressor engaged.

If it is possible, please send me the pressure readings. Here is a link which shows how to properly recharge and check pressures. Additionally, if the pressures are normal and it still is not turning off, we will need to look at a wiring schematic to determine what the possible cause is.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

This link discusses possible issues with it not getting cold. Toward the bottom of the page, it discusses the pressure sensor.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

I hope this is helpful. Let me know if you can get the readings, and remember, if the car's defroster is turned on, the AC compressor will engage to dehumidify the air.

Take care,
Joe